Effects of sensitization of trigeminovascular neurons to triptan therapy during migraine.

Migraine is a neurological disorder which leads to recurring, unilateral, throbbing headache, associated with variable incidence of aura (i.e., visual, sensory and motor function disturbances), nausea and vomiting, photophobia and phonophobia, fatigue, and enhanced irritability. We have recently shown that migraine headache is also associated with high incidence of ipsilateral cutaneous allodynia, particularly in periorbital and temporal skin areas. Patients who experience cutaneous allodynia during migraine feel that their skin hurts in response to otherwise innocuous activities such as combing, shaving, taking a shower, or wearing glasses or earrings. Here, we present evidence to support the view that the development of throbbing in the initial phase of migraine is mediated by sensitization of peripheral trigeminovascular neurons that innervate the meninges, and that the development and maintenance of cutaneous allodynia later in the attack is propelled by sensitization of central trigeminovascular neurons which receive converging sensory input from the meninges as well as from the scalp and facial skin. We also present evidence that the development of cutaneous allodynia during migraine is detrimental to termination of acute migraine attacks using triptans (5HT1B/1D receptor agonist).